Cardiovascular System


• Two divisions


• Two divisions: pulmonary


• Two divisions: pulmonary & systemic


• Pulmonary Division

–Blood flows from heart



–Blood flows from heart to alveolar capillaries



–Blood flows from heart to alveolar capillaries and back to heart


• Systemic Division



– Blood flows from heart



– Blood flows from heart to all tissue capillaries



– Blood flows from heart to all tissue capillaries (except alveolar capillaries)



– Blood flows from heart to all tissue capillaries (except alveolar capillaries) and back to heart

• Pulmonary arteries carry blood:


High in O2, low in CO2


High in O2

Low in O2 Low in O2 high in CO2

High in O2, low in CO2

• Heart

• Heart

– Location

• Heart

– Location: mediastinum

• Heart

– Location: mediastinum

– Size?

• Pericardium

• Pericardium: protective sac surrounding the heart


–Visceral pericardium


–Visceral pericardium

– Parietal pericardium

• Layers of the heart wall


– endocardium


– endocardium

– myocardium


– endocardium

– myocardium

– epicardium


– endocardium

– myocardium

– epicardium (same as the visceral pericardium)

• Chambers of the heart


– Receiving chambers:


– Receiving chambers: atria


– Receiving chambers: atria (singular:


– Receiving chambers: atria (singular: atrium)


– Receiving chambers: atria (singular: atrium)

–Pumping chambers: ventricles

• Right ventricle

• Right ventricle: pump for the pulmonary circulation


• Left ventricle


• Left ventricle: pump for the systemic circulation

• “Great Vessels” of the Heart

– Aorta

– Pulmonary Trunk

Inferior vena cava

Superior vena cava Pulmonary

trunk

Pulmonary veinsAorta

RPALPA

• Heart valves

• Heart valves: ensure one-way flow of blood through heart

– Semilunar valves


• pulmonary semilunar


• pulmonary semilunar

• aortic semilunar

• Atrio-ventricular (AV) valves


• tricuspid


• tricuspid

• bicuspid


• tricuspid

• bicuspid (mitral)


• tricuspid

• bicuspid (mitral) Associated with papillary

muscles


• tricuspid

• bicuspid (mitral) Associated with papillary

muscles and chordae tendinae

• Skeleton of the heart

– set of 4 fibrous rings near base of heart

• Skeleton of the heart, con’t.

– provides rigidity to prevent the dilation of valves

– provides a point of attachment for valves

• Skeleton of the heart, con’t.

– electrically isolates the atria from the ventricles.

•The A-V bundle (“bundle of His”) is the only electrical connection between the atria and the ventricles

• Path of Blood Flow Through the Heart

http://www.innerbody.com/anim/heart.html

• Heart Sounds

–1st sound (“lub”)

• closing of the AV valves

– 2nd sound (“dup”)

• closing of the semilunar valves

Conduction System of the Heart

Sinoatrial node

Atrioventricular node

AV bundle

Purkinje fibers

Bundle branches

• Blood Vessels

1. Arteries

2. Arterioles

3. Capillaries

4. Venules

5. Veins

• All blood vessels are lined with endothelium

1. Arteries

• Carry blood away from the heart

• Subject to the highest blood pressure

1. Arteries

• Carry blood away from the heart

• Subject to the highest blood pressure

• Located deep

– Structure of Arteries

•Tunica interna

•Tunica media

•Tunica externa

• Types of arteries

– Elastic arteries

• Contain elastic fibers in the tunica media and interna

•Largest arteries

• Types of arteries

– Muscular arteries• Little elasticity• Abundant smooth muscle in tunica media

2. Arterioles

• < 1mm in diameter

• Endothelium and smooth muscle

2. Arterioles

• < 1mm in diameter

• Endothelium and smooth muscle

• Metarterioles regulate flow of blood into capillaries

2. Arterioles• < 1mm in diameter• Endothelium and smooth

muscle • Metarterioles regulate flow

of blood into capillaries • Help regulate blood

pressure

3. Capillaries• Sites of exchange

exchange between blood and tissue cells in systemic caps

exchange between blood and air in pulmonary caps

• Very permeable

4. Veins

• Return blood back towards heart

• Smallest veins: venules

• Veins have 3 layers like arteries

• Differences between arteries and veins

– thinner

– larger diameter

– located both deep and superficial

– veins have valves

Distribution of Blood

• Coronary Circulation

– Blood flow to and from the myocardial capillaries

• Some vessels of the coronary circuit– Right coronary artery– Left coronary artery

• circumflex• anterior interventricular (also: LAD)

– Coronary sinus

• Hepatic Portal Circulation

• Features of fetal heart

– Foramen ovale

– Ductus arteriosus

• Other features of fetal circulation

– Umbilical arteries and veins

– Ductus venosus

• Changes in fetal circulation after birth

– foramen ovale closes

– ductus arteriosus closes

Coronary Artery Disease

• Degenerative changes in coronary arteries

• Often associated with arterial plaques

Cardiovascular System

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